Multifocal motor neuropathy

- autoimmune neuropathy (absence of sensory features)
- distal weakness, asymmetrical
- progressive weakness affecting an isolated limb
- early on in the disease there is profound weakness disproportionate to the amount of wasting
- fasciculation can occur in the affected muscle
- it is localised to individual peripheral nerve, which in contrast to the pattern of MND that is myotomal
- important differential diagnosis of motor neurone disease (MND) because it is TREATABLE
- nerve conduction study : multifocal demyelination and motor conduction block (vs axonal degeneration in MND)
- positive anti-ganglioside GM1 antibodies
- treatment : IV immunoglobulins or cyclophosphamide. Avoid steroid because they exacerbate weakness